A study does not provide evidence that mask-wearing causes long COVID

By: Nikolaj Kristensen
May 5 2023

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A study does not provide evidence that mask-wearing causes long COVID


The Verdict False

A flawed study does not prove that mask-wearing causes long COVID symptoms.

Claim ID 1a3f6f7f


A study published in the multi-disciplinary open-access journal, Frontiers in Public Health on April 5, 2023, concludes that mask-wearing can be linked to symptoms that may have been previously misinterpreted as long COVID symptoms. This has prompted questions on Facebook and Twitter about whether mask-wearing causes long COVID. However, the study is flawed, and experts find the connection unlikely.

In Fact

The study is a meta-analysis that reviews other studies. Therefore, it poses no new evidence that mask-wearing causes long COVID symptoms. The summary of the study is such that, in their review, masks interfere with the body’s uptake of oxygen and release of carbon dioxide leading to, among other things, headaches and dizziness, which are also symptoms of long COVID. 

However, Eric Burnett, MD at Columbia University Irving Medical Center, has pointed out several issues with the study. To start, there were minimal relative differences in oxygen and carbon dioxide levels found in the blood of those wearing masks and those who didn’t. Moreover, the analysis heavily favors a study that focused on 97 patients with a condition known to cause severe breathing problems, so cannot be generalized. Another expert, Kasper Iversen, Clinical Professor at Copenhagen University Department of Clinical Medicine, says it is “very unlikely” that long COVID symptoms are caused by mask-wearing. 

A Forbes article cited further experts in its coverage of the study, who called it “deeply flawed,” guilty of “jumping to conclusions,” “cherry-picking,” and “comparing apples to oranges.” PolitiFact recently dissected another study making similar arguments by one of the same authors, Kai Kisielinski, who describes himself as an independent researcher. 

Jeremy Howard, a scientist at the University of San Francisco, told PolitiFact that the study overestimated by 60 times the amount of carbon dioxide people breathe when wearing masks. Howard added that he wasn’t aware of any research showing mask usage to cause serious health problems. “Many occupations require extended mask usage, so if there was such a link, we would have clearly seen it from that data,” said Howard.

Mask usage has been proven effective at preventing virus spread. A 2021 meta-study found that mask-wearing was associated with reductions in the incidence of COVID-19, while a study by Science found masks to be particularly effective in combination with other preventive measures such as ventilation and distancing.  

The Verdict

A recent study has caused debate as to whether mask-wearing can cause long COVID symptoms. However, the study is flawed, and experts find it unlikely such a connection exists, as mask usage is not known to cause serious health problems. The author is an independent researcher with a history of heavily criticized papers. Therefore, we have marked this claim as false.

The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19, including symptoms, prevention, and available treatment, please refer to the World Health Organization or your national healthcare authority.

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